Demonstration slide rule support



June 6, 1967 A. H. RIFE ET AL 3,323,

DEMONSTRATION SLIDE RULE SUPPORT Filed June 17, 1965 2 Sheets-Sheet 1 m/aim Fwd/70 BY fflaeirr 67/1/14 2 June 6, 1967 R|FE ET AL DEMONSTRATION SLIDE RULE SUPPORT 2 Sheets-Sheet 2 Filed June 17, 1965 a W in. E w/ fi AW m m 507 4 QM m United States Patent 3,323,769 DEMONSTRATION SLIDE RULE SUPPORT Alfred H. Rife, 78 W. Norman Ave., Arcadia, Calif.

91006; Angelo Romito, 1418 Oak Circle Drive, Glendaie, (Ialif. 91208; and Forrest R. Bunker, 525 N.

Segovia, San Gabriel, Calif. 91775 Filed June 17, 1965, Ser. No. 464,667 6 Claims. (Cl. 248330) This invention relates to a mounting device and in particular to a retractable apparatus for mounting demonstration devices such as large slide rules.

Among the many visual aids which are currently in use in introductory engineering and science classes are large demonstration size slide rules. These rules are normally five to eight feet in length and are used to instruct students in the operation of such engineering tools.

Storage of such aids is frequently a problem. In some cases the rule is simply hung on the front wall of the class from a pair of brackets and left permanently in place. This is usually unsatisfactory because when so suspended it either overlaps useful blackboard space or is too far out or reach. In addition, difficulty is encountered in turning the rule over to use the other side. In other cases, the slide rule is frequently made so that it is demountable from its supports so that it can be stored elsewhere when not in use. A third alternative is to locate it on what is otherwise unoccupied wall space. Neither of these latter two alternatives is very expenditious because they involve the inconvenience on the one hand of mounting, unmounting and storing, and on the other, the problem of finding unused space and inefficient utilization of such space where a special place is made for it. There is also the danger that the rule may unexpectedly fall from such a mounting and injure someone standing below it.

In eliminating these problems, the present invention provides a permanent mounting for a demonstration device such as a slide rule which is retractable at a touch. The invention comprises a backboard on which is mounted a pair of supporting brackets. A pair of rings are pivotally attached at a point on the exterior circumference of the rings to each of the supporting brackets. A second pair of rings concentric with the first pair are mounted interiorly of the first pair and means are provided for rotating the second pair relative to the first. The demonstration slide rule is attached to the second pair of rings. A coil spring reel is attached to the rear of the backboard and serves as a means for reeling and unreeling a pair of cables which run from the reel to the first pair of rings. The cables pass through apertures in the backboard adjacent each of the supporting brackets and pass over and around two pairs of pulleys located between the apertures and the reel. The pulleys are used to alter the direction of travel of the cables between the reel and pivot rings. The tension on the cable reel spring is set such that slight upward and downward pressure at any point on the slide rule causes it to be moved between the storage and demonstration positions without binding or locking at a point intermediate the two end positions.

With such a device the rule is always available and capable of being put into use. Since the rule is permanently mounted, no special storage is needed; the rule is 3,323,769 Patented June 6, 1967 Shown in FIG. 1 is a demonstration slide rule 8 which has been lowered into the demonstration position. The rule is mounted on a support 10 consisting of a backboard 12 and brackets 14 mounted on the backboard. The brackets support a pair of rings 16 which are pivotally attached to the brackets. Mounted interiorly of the pivoting rings 16 are a pair of roller rings 18. The roller rings are provided with a groove on their outer surface which mates with a plurality of rollers 20 disposed along and projecting inwardly from the interior circumference of the pivoting rings 16. The roller rings 18 are seated on the rollers 20 to permit unimpeded rotation within the pivot rings 16 in either direction.

Mounting brackets 22 are provided on the interior side of the roller rings 18 for providing means whereby the slide rule 8 can be attached to and mounted on the support structure of this invention. A pair of cables 24 extend from a point on the exterior peripheral surface of the pivot rings back toward the backboard and pass through a pair of apertures 26 to the rear of the backboard. Primary support for the rings and slide rule come from the brackets and pivot points of rings 16. Secondary support and the means for holding the rule in the demonstration and storage position is provided by the cables 24.

The slide rule is shown with its slider displaced and passing through one of the roller rings to illustrate how the unique construction of the support in no way obstructs the use of the rule.

FIG. 2 depicts the disposition of the cables along the rear of the backboard. As will be shown in FIG. 3, the backboard is offset from the wall on which it is mounted in order to provide a space for pulleys and a coil-spring reel for retracting and deploying the cables which attach to the slide rule support. After passing through apertures 26, cables 24 pass over a pair of pulleys 30 and downwardly toward the base of the backboard and around pulleys 32 which translate the motion of the cable from the vertical to nearly horizontal and turn the direction of cable travel at right angles to its former direction. A coil-spring reel 34 provided in the center of the backboard is mounted on a shaft which is Welded to a steel plate 36. The plate is in turn bolted to the backboard. The reel exerts a decremental pull on the cables ranging for approximately 14 pounds at full deployment to approximately 3 pounds at full retraction. The pair of cables are wound on the same reel and are stored thereon when the slide rule is raised into its storage position.

By virtue of the use of a single reel, upward pressure regardless of where applied along the length of the rule causes the transfer of a balancing amount of tension to the cable which is most remote from the point of pressure application. The result is a uniform and balanced transition between operating and storage positions without skewed locking or cocking of the rule intermediate these positions.

The details of the relationship of the roller rings and pivot rings are shown in FIG. 3. In this figure, the demonstration device is shown in the raised or storage position. In this position the cables are fully retracted onto the coil-spring reel. This view shows the olfset 37 on which backboard 12 is mounted to provide space for the cable reel and pulleys between the backboard and the wall to which the entire assembly is attached. One of the pair of supporting cables is shown herein. It runs from the coil-spring reel (not shown) around pulley 32 up and over pulley 30 and thence to a point of attachment 46 on pivot ring 16.

Pivot ring 16 is attached to mounting bracket 14 at pivot point 38 and is free to rotate about this point. In the preferred embodiment, the pivot is provided with an oil-less bearing. Rollers 20 are mounted in indentations 44 provided along the interior circumference of pivot ring 16. These rollers are mounted by means of pins 42 and are adapted to engage and travel in groove 40 provided in the outer surface of roller ring 18. In the preferred embodiment, these rollers are fabricated from nylon. The demonstration slide rule to be mounted on the support of this invention is attached to roller ring 18 by means of brackets 22.

In operation the slide rule is stored in the position shown in FIG. 3. When it is desired to lower it into the operating or demonstration position, outward and downward pressure on a pivot ring or the slide rule causes the cables 24 to unreel from the coil spring reel and the pivot rings to rotate about pivot 38 until the rule is lowered into the position shown in FIG. 1. By proper balancing of the weight of the slide rule and the tension on the coil spring, only a slight amount of pressure is necessary to cause the device to descend to the operating position.

Once it has been lowered into the operating position and one side of the rule is displayed toward the class, lessons can be given utilizing it, and the slider operated with ease by virtue of the mounting such that the slider of the rule can pass through the roller-rings 18 without obstruction. When it is desired to use the other side of the slide rule, the slide rule is grasped and rotated. The roller rings 18 turn freely on rollers 20' until the other side of the rule is exposed to the class.

When a particular lesson has ended and it is desired to take the slide rule out of action, a small amount of pressure is applied to the rings or the slide rule and tension in the coil-spring reel causes the cables to berreeled in over the pulleys and wound onto the reel until the device is restored to the storage position shown in FIG. 3.

What is claimed is:

1. A mounting and display device for use with an elongated demonstration-size article comprising;

mounting means adapted to be secured to a vertical surface,

a first pair of supports, each of said supports being pivotally attached to said mounting means and circumscribing an annular opening,

a second pair of supports mounted on said first pair of supports, means for rotating said second pair of supports relative to said first pair of supports,

means for attaching the demonstration article to the second pair of supports,

a single coil spring for counterbalancing the weight of said article, and a pair of flexible auxiliary supports, each of said pair of auxiliary supports extending from opposite sides of the coil spring to each of the first pair of supports whereby slight pressure causes the demonstration article to 'be moved parallel to itself without cocking.

2. A mounting and display device for use with a large demonstration-size article comprising:

mounting means adapted to be secured to a vertical surface,

a first pair of rings attached to said mounting means and being pivotally movable relative thereto,

a plurality of rollers disposed along the periphery of each of said first pair of rings, 7

a second pair of rings mounted on said rollers, each of said second pair of rings being provided with a groove located on the exterior peripheral surface thereof and adapted to be engaged by said rollers,

means for attaching the demonstration article to the second pair of rings, and

means for counterbalancing the weight of the demonstration article whereby slight pressure causes said article to be moved between operating and storage positions.

3. A mounting and display device for use with a large demonstration-size article comprising:

a backboard,

a pair'of supporting brackets mounted on said backboard,

a first pair of rings, each of said rings being pivotally attached to one of said supporting brackets,

a plurality of rollers disposed along the interior periphery of each of the first pair of rings,

a second pair of rings mounted on said rollers,

means for attaching the demonstration articles to the second pair of rings,

a coil-spring reel mounted on the side of the backboard opposite the brackets,

a pair of apertures in the backboard,

a pair of cables, each of said pair being attached at one end to one of the first pair of rings, at the other eng to said reel and passing through said apertures, an

means for guiding said cables from said apertures to said reel whereby slight pressure causes said article to be moved between operating and storage positions.

4. A mounting and display device according to claim 3 wherein said second pair of rings are of a diameter such that a slider on said demonstration article can be passed therethrough.

5. A mounting and display device for use with a classroom size demonstration slide rule comprising:

a backboard,

a pair of supporting brackets mounted on said backboard,

.a first pair of rings, each of said rings being pivotally attached to one of said supporting brackets,

a plurality of rollers disposed along the interior periphery of each of the first pair of rings and projecting into the area circumscribed by each of said rings,

a second pair of rings mounted interiorly of said first pair of rings on said rollers, each of said second pair being provided with a groove located on the exterior peripheral surface thereof and adapted to be engaged by said rollers,

a plurality of mounting brackets for attaching the slide rule to the second pair of rings,

a coil spring reel mounted on the side of the backboard opposite the supporting brackets,

a pair of apertures in the backboard located adjacent the brackets,

pulley means mounted on the rear of the backboard,

and

a pair of cables, each of said pair being attached at one end to one of the first pair of rings and at the other end to the coil spring reel and passing through the apertures in the background and around the pulley moved between operating and storage positions.

6. A mounting and display device in accordance with claim 5 wherein the pulley means mounted on the rear of the backboard each comprise two pulleys, the first of said pulleys being mounted below and adjacent to the aperture in said backboard, the second of said pulleys being mounted below the first and oriented such that its axis of rotation is perpendicular to the axis of rotation of said first pulley whereby the supporting cables pass over and down from said first pulleys and around said second pulleys such that their direction of travel from said second pulleys to said reel is substantially parallel to the backboard.

References Cited UNITED STATES PATENTS 1,286,376 12/1918 Madsen et al 248-251 X 1,326,650 12/1919 Doerr 248-284 1,617,028 2/1927 Rekar 248-330 X 2,410,602 11/1946 -Davis 308183 2,679,442 5/ 1954 Koerner et al 248284 X 3,172,632 3/1965 Borg 248201 CHANCELLOR E. HARRIS, Primary Examiner.

CLAUDE A. LE ROY, Examiner.

R. P. SEITTER, Assistant Examiner.

means whereby slight pressure causes said rule to be 

1. A MOUNTING AND DISPLAY DEVICE FOR USE WITH AN ELONGATED DEMONSTRATION-SIZE ARTICLE COMPRISING: MOUNTING MEANS ADAPTED TO BE SECURED TO A VERTICAL SURFACE, A FIRST PAIR OF SUPPORTS, EACH OF SAID SUPPORTS BEING PIVOTALLY ATTACHED TO SAID MOUNTING MEANS AND CIRCUMSCRIBING AN ANNULAR OPENING, A SECOND PAIR OF SUPPORTS MOUNTED ON SAID FIRST PAIR OF SUPPORTS, MEANS FOR ROTATING SAID SECOND PAIR OF SUPPORTS RELATIVE TO SAID FIRST PAIR OF SUPPORTS, MEANS FOR ATTACHING THE DEMONSTRATION ARTICLE TO THE SECOND PAIR OF SUPPORTS, A SINGLE COIL SPRING FOR COUNTERBALANCING THE WEIGHT OF SAID ARTICLE, AND A PAIR OF FLEXIBLE AUXIALIARY SUPPORTS, EACH OF SAID PAIR OF AUXILIARY SUPPORTS EXTENDING FROM OPPOSITE SIDES OF THE COIL SPRING TO EACH OF THE FIRST PAIR OF SUPPORTS WHEREBY SLIGHT PRESSURE CAUSES THE DEMONSTRATION ARTICLE TO BE MOVED PARALLEL TO ITSELF WITHOUT COCKING. 